/* ===== Theme Variables ===== */
:root,
[data-theme="light"] {
  --bg: #ffffff;
  --bg-secondary: #f6f8fa;
  --text: #1f2328;
  --text-secondary: #656d76;
  --border: #d0d7de;
  --link: #0D4723;
  --link-hover: #093618;
  --pill-bg: #f6f8fa;
  --pill-bg-active: #0D4723;
  --pill-text: #1f2328;
  --pill-text-active: #ffffff;
  --code-bg: #f6f8fa;
  --blockquote-border: #d0d7de;
  --blockquote-text: #656d76;
  --table-border: #d0d7de;
  --table-row-alt: #f6f8fa;
  --toggle-bg: #e8e8e8;
}

[data-theme="dark"] {
  --bg: #000000;
  --bg-secondary: #0d1117;
  --text: #b8c0cc;
  --text-secondary: #6e7681;
  --border: #30363d;
  --link: #2d9a50;
  --link-hover: #37b55f;
  --pill-bg: #0d1117;
  --pill-bg-active: #2d9a50;
  --pill-text: #b8c0cc;
  --pill-text-active: #000000;
  --code-bg: #0d1117;
  --blockquote-border: #30363d;
  --blockquote-text: #6e7681;
  --table-border: #30363d;
  --table-row-alt: #0d1117;
  --toggle-bg: #21262d;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--text);
  background-color: var(--bg);
  transition: background-color 0.2s ease, color 0.2s ease;
}

/* ===== Header & Navigation ===== */
.site-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 1.5rem 2rem 1rem;
  max-width: 860px;
  margin: 0 auto;
  gap: 1rem;
}

.nav-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  flex: 1;
}

.pill {
  display: inline-block;
  padding: 0.35rem 1rem;
  border-radius: 9999px;
  background: var(--pill-bg);
  color: var(--pill-text);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  border: 1px solid var(--border);
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
  white-space: nowrap;
}

.pill:hover {
  background: var(--pill-bg-active);
  color: var(--pill-text-active);
  border-color: var(--pill-bg-active);
}

.pill.active {
  background: var(--pill-bg-active);
  color: var(--pill-text-active);
  border-color: var(--pill-bg-active);
}

.theme-toggle {
  background: var(--toggle-bg);
  border: 1px solid var(--border);
  border-radius: 9999px;
  cursor: pointer;
  padding: 0.45rem 0.65rem;
  font-size: 0.875rem;
  line-height: 1;
  flex-shrink: 0;
  color: var(--text);
  display: flex;
  align-items: center;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.theme-toggle:hover {
  border-color: var(--text-secondary);
}

[data-theme="light"] .icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }

/* ===== Content ===== */
.content {
  max-width: 860px;
  margin: 0 auto;
  padding: 1rem 2rem 4rem;
}

/* ===== GitHub-style Markdown Body ===== */
.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
  margin-top: 1.5em;
  margin-bottom: 0.5em;
  font-weight: 600;
  line-height: 1.25;
}

.markdown-body h1 { font-size: 2em; padding-bottom: 0.3em; border-bottom: 1px solid var(--border); }
.markdown-body h2 { font-size: 1.5em; padding-bottom: 0.3em; border-bottom: 1px solid var(--border); }
.markdown-body h3 { font-size: 1.25em; }
.markdown-body h4 { font-size: 1em; }
.markdown-body h5 { font-size: 0.875em; }
.markdown-body h6 { font-size: 0.85em; color: var(--text-secondary); }

.markdown-body p {
  margin-top: 0;
  margin-bottom: 1em;
}

.markdown-body a {
  color: var(--link);
  text-decoration: none;
}

.markdown-body a:hover {
  text-decoration: underline;
  color: var(--link-hover);
}

.markdown-body strong {
  font-weight: 600;
}

.markdown-body img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
}

/* Lists */
.markdown-body ul,
.markdown-body ol {
  margin-bottom: 1em;
  padding-left: 2em;
}

.markdown-body li {
  margin-bottom: 0.25em;
}

.markdown-body li + li {
  margin-top: 0.25em;
}

/* Code */
.markdown-body code {
  background: var(--code-bg);
  border-radius: 6px;
  padding: 0.2em 0.4em;
  font-size: 85%;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

.markdown-body pre {
  background: var(--code-bg);
  border-radius: 6px;
  padding: 1em;
  overflow-x: auto;
  margin-bottom: 1em;
  border: 1px solid var(--border);
}

.markdown-body pre code {
  background: transparent;
  padding: 0;
  font-size: 85%;
  line-height: 1.45;
}

/* Blockquotes */
.markdown-body blockquote {
  border-left: 0.25em solid var(--blockquote-border);
  color: var(--blockquote-text);
  padding: 0 1em;
  margin: 0 0 1em 0;
}

/* Tables */
.markdown-body table {
  border-collapse: collapse;
  width: 100%;
  margin-bottom: 1em;
}

.markdown-body table th,
.markdown-body table td {
  border: 1px solid var(--table-border);
  padding: 0.5em 0.75em;
  text-align: left;
}

.markdown-body table tr:nth-child(even) {
  background: var(--table-row-alt);
}

.markdown-body table th {
  font-weight: 600;
  background: var(--bg-secondary);
}

/* Horizontal Rule */
.markdown-body hr {
  height: 0.25em;
  padding: 0;
  margin: 1.5em 0;
  background-color: var(--border);
  border: 0;
  border-radius: 2px;
}

/* ===== File List (folder pages) ===== */
.file-list {
  list-style: none;
  padding-left: 0;
  margin-top: 1em;
}

.file-list li {
  padding: 0.5em 0;
  border-bottom: 1px solid var(--border);
}

.file-list li:first-child {
  border-top: 1px solid var(--border);
}

.file-list li a {
  color: var(--link);
  text-decoration: none;
  font-weight: 500;
}

.file-list li a:hover {
  text-decoration: underline;
  color: var(--link-hover);
}

/* ===== Page date ===== */
.page-date {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: 1.5em;
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .site-header {
    padding: 1rem 1rem 0.75rem;
  }
  .content {
    padding: 1rem 1rem 3rem;
  }
}